Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Artificial joints generally require mechanisms to control their movement. For example, an artificial knee joint or a prosthetic joint will be prescribed for a person with a through-knee (TK) or an above-knee (AK) amputation (i.e., a person without a knee joint, shank, and/or foot). For a person with such an amputation, the ability for the knee to bend or articulate during sitting, kneeling, or ambulating may be desirable. It may also be desirable to have the ability to control the leg during the swing-phase of the gait when the person is walking or running, in order to prevent the heel from excessively rising off the ground and excessive terminal impact, for example. By improving control, the gait may also be improved to make the gait look more natural. Finally, the joint may need to provide sufficient support to the person in the form of stability and structural integrity. Therefore there is a need for improved joint structures and controllers.